Practical applicability of processing static, short-observation-time raw GNSS measurements provided by a smartphone under tree vegetation

Abstract

In this study we investigate practical feasibility and horizontal accuracy of 10-minute long static GNSS measurements acquired using an Android-based Xiaomi Mi8 smartphone. Measurements were collected during 40 days on three points with different tree canopy conditions. The accuracy was analyzed with regard to measurement conditions, usage of ground plane, application of different frequencies, and processing methods. The possibility to achieve even centimeter-level accuracy under open-sky conditions was confirmed, but the vegetation significantly reduces the positioning performance. Although the carrier-phase-based solutions provided the best results in some cases, these are prone to very high variability of results. The code-based measurements can be more important, as these are available for all smartphones with Android 7 or higher (in contrast with carrier-phase measurements), and provided sub-meter accuracy under optimal conditions and accuracy better than standard smartphone positioning methods under conditions with tree canopy.